Can someone tell me what the difference is between a 2 row malt and a 6 row malt. I really want to get into buying bulk, but I need a little advise. I don't want to make a mistake when ordering such large quantities. I like Pale Ales... Any suggestions regarding ordering bulk?

1) Two Row Barley vs. 6-Row : My source: "New Brewing Lager Beer", by Gregory J. Noonan, 1996 ed. [excellent, comprehensive source on beer brewing in general, better that all other books I have.] 2 paragraphs from the first chapter:
"European brewers prefer superior two-row, thin-husked, large berried barley varieties, which give the best brew-house yield, clarity, and flavor. These have a more favorable starch-to-protein/husk ratio than other barleys and yield a mellow flavor and good clarity.
Six-row barley is the most economical to grow because the greater number of rows per head increases the per-acre yield. It is a warm-climate barley and is the type most widely grown in the United States. It is favored by domestic commercial breweries because it is rich in the enzymes needed to convert the adjuncts they employ (adjuncts may account for up to 60 percent of the extract in U.S. brews). Because six-row barley is high in protein, in all-malt brews it presents problems with clarity and stability. Its higher husk content improves mash filterability but can contribute harsh flavors, especially when brew-house practices cause hot-side aeration. "
Online source: http://www-2.cs.cmu.edu/~pwp/tofi/liz_brewing.html "Elizabethan Homebrewing", by Tofi Kerthjalfadsson
British, Belgian, German, and American malts are all somewhat different. British Pale malt comes from a 2-row variety of barley, is allowed to sprout for a somewhat longer period of time, thus more of the very long starches are modified [Noonan, Lager, pp. 87 1983 ed], and is kilned at a reasonably low temperature. The Belgian and German malts are often less modified, and kilned differently. The American malts are most often 6-row barley, which is a different, modern strain of barley. Most homebrewing stores either carry British Pale malt, or can get it.

In my brewery we use Great Western 2-row malt as our base malt for all our ales. If you are not adding cereal adjunct to your mash stay away from 6-row malts. The large commercial breweries use 6-row because it provides them with a higher nitrogen and enzyme content to convert the starch that is added with the cereal adjuncts (corn, rice, wheat).

If you can afford English 2-row over the domestic it will add more authenticity to your ale, but ether will work.